Mind Over Manners: This is not usually much of an issue with standard-issue Psychic Powers, which in the Eldraeverse are essentially organic neural WiFi, designed for communication and not permitting arbitrary mindreading (you need a SQUID and some rather complex software for that), but the Common Social Protocol does include detailed etiquette for farspeech, appropriate levels of exchange, etc., in just the same way as it does for, well, regular speech.
Of course, there are psychedesigners and redactors and sophotechnologists and other people who can use other means of mind reading and control. In their case, it’s played very straight with their professional standards – often enforced (in the case of most, by professional bodies; in the case of the Eupraxic Collegium and Guardians of Our Harmony, by law) using its own means; i.e., to practice professionally, you volunteer to have your colleagues regularly examine your mind to make sure that your ethical standards are where they should be. And, of course, most violations of them also violate the criminal law.
(Which is why you don’t want to go to a back-street psychedesigner, because there’s usually a reason why they don’t have a guild certificate.)
Generally, if you want a back-street psychdesigner, it’s because they don’t have guild certificate and are willing (and able, in the literal sense) to do things that holders of guild certificate do not. Things like erasing inconvenient incriminating memories, not-exactly-voluntarily tweaking few parameters on third parties and so on. Illegal as hell, but there probably is a market…